A process for depositing a metal coating via the decomposition of volatile metal compounds using a glow discharge is disclosed in U.S. Pat. No. 6,221,440. The chemical and photochemical reduction of precursor metal salts to form metallic films and powders is disclosed in U.S. Pat. Nos. 6,262,129; 5,850,047 and 5,281,447. The modification of organometallic salts using organic reactants for the formation of films and powders is disclosed in U.S. Pat. Nos. 6,197,366 and 4,463,030.
The use of various coating processes to apply a metallurgical coating to ferrous-based powders, which are pressed and sintered to diffuse the coating into the powder, is disclosed in U.S. Pat. No. 6,251,339. The low temperature chemical vapor deposition synthesis of metallic films is disclosed in U.S. Pat. Nos. 5,503,874; 5,494,704 and 5,292,594.
Precious metal-based catalysts and transition metal-based catalysts have been used to purify exhaust gases containing carbon monoxide, nitrogen oxide, and hydrocarbons. The use of catalysts in smoking articles is disclosed in U.S. Pat. Nos. 4,317,460; 4,956,330; 5,050,621; 5,258,340 and 5,446,003.
Despite the developments to date, there is interest in improved and more efficient methods for preparing intermetallic thin films and powders. Preferably, such methods and compositions should not involve expensive or time consuming manufacturing and/or processing steps. There also is interest in improved and more efficient methods and compositions for reducing the amount of targeted gaseous species in the mainstream smoke of a cigarette during smoking.